osu/osu.Game/Graphics/Containers/LogoTrackingContainer.cs

158 lines
5.6 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Utils;
using osu.Game.Screens.Menu;
using osuTK;
namespace osu.Game.Graphics.Containers
{
/// <summary>
/// A container that handles tracking of an <see cref="OsuLogo"/> through different layout scenarios.
/// </summary>
public class LogoTrackingContainer : Container
{
public Facade LogoFacade => facade;
protected OsuLogo Logo { get; private set; }
private readonly InternalFacade facade = new InternalFacade();
private Easing easing;
private Vector2? startPosition;
private double? startTime;
private double duration;
/// <summary>
/// Assign the logo that should track the facade's position, as well as how it should transform to its initial position.
/// </summary>
/// <param name="logo">The instance of the logo to be used for tracking.</param>
/// <param name="duration">The duration of the initial transform. Default is instant.</param>
/// <param name="easing">The easing type of the initial transform.</param>
public void StartTracking(OsuLogo logo, double duration = 0, Easing easing = Easing.None)
{
if (logo == null)
throw new ArgumentNullException(nameof(logo));
if (logo.IsTracking && Logo == null)
throw new InvalidOperationException($"Cannot track an instance of {typeof(OsuLogo)} to multiple {typeof(LogoTrackingContainer)}s");
if (Logo != logo && Logo != null)
{
// If we're replacing the logo to be tracked, the old one no longer has a tracking container
Logo.IsTracking = false;
}
Logo = logo;
Logo.IsTracking = true;
this.duration = duration;
this.easing = easing;
startTime = null;
startPosition = null;
}
/// <summary>
/// Stops the logo assigned in <see cref="StartTracking"/> from tracking the facade's position.
/// </summary>
public void StopTracking()
{
if (Logo != null)
{
Logo.IsTracking = false;
Logo = null;
}
}
/// <summary>
/// Gets the position that the logo should move to with respect to the <see cref="LogoFacade"/>.
/// Manually performs a conversion of the Facade's position to the Logo's parent's relative space.
/// </summary>
/// <remarks>Will only be correct if the logo's <see cref="Drawable.RelativePositionAxes"/> are set to Axes.Both</remarks>
protected Vector2 ComputeLogoTrackingPosition()
{
var absolutePos = Logo.Parent.ToLocalSpace(LogoFacade.ScreenSpaceDrawQuad.Centre);
return new Vector2(absolutePos.X / Logo.Parent.RelativeToAbsoluteFactor.X,
absolutePos.Y / Logo.Parent.RelativeToAbsoluteFactor.Y);
}
protected override void Update()
{
base.Update();
if (Logo == null)
return;
if (Logo.RelativePositionAxes != Axes.Both)
throw new InvalidOperationException($"Tracking logo must have {nameof(RelativePositionAxes)} = Axes.Both");
// Account for the scale of the actual OsuLogo, as SizeForFlow only accounts for the sprite scale.
facade.SetSize(new Vector2(Logo.SizeForFlow * Logo.Scale.X));
var localPos = ComputeLogoTrackingPosition();
if (LogoFacade.Parent != null && Logo.Position != localPos)
{
// If this is our first update since tracking has started, initialize our starting values for interpolation
if (startTime == null || startPosition == null)
{
startTime = Time.Current;
startPosition = Logo.Position;
}
if (duration != 0)
{
double elapsedDuration = (double)(Time.Current - startTime);
float amount = (float)Interpolation.ApplyEasing(easing, Math.Min(elapsedDuration / duration, 1));
// Interpolate the position of the logo, where amount 0 is where the logo was when it first began interpolating, and amount 1 is the target location.
Logo.Position = Vector2.Lerp(startPosition.Value, localPos, amount);
}
else
{
Logo.Position = localPos;
}
}
}
protected override void Dispose(bool isDisposing)
{
if (Logo != null)
Logo.IsTracking = false;
base.Dispose(isDisposing);
}
private class InternalFacade : Facade
{
public new void SetSize(Vector2 size)
{
base.SetSize(size);
}
}
/// <summary>
/// A dummy object used to denote another object's location.
/// </summary>
public abstract class Facade : Drawable
{
public override Vector2 Size
{
get => base.Size;
set => throw new InvalidOperationException($"Cannot set the Size of a {typeof(Facade)} outside of a {typeof(LogoTrackingContainer)}");
}
protected void SetSize(Vector2 size)
{
base.Size = size;
}
}
}
}